Celtic survived a late scare at St Johnstone to make it eight straight wins in 2015 and establish a six point lead at the top of the Premiership.

With the home defence dozing, Leigh Griffiths raced clear to slot home after just 35 seconds.

Stefan Johansen stretched Celtic's lead with a neat finish on 52 minutes.

But Saints' Michael O'Halloran knocked in a loose ball and Celtic keeper Craig Gordon needed to make an outstanding save to deny Dave Mackay an equaliser.

Mackay looked certain to score as he hammered in a shot from 10 yards following Gordon's stop from a Brian Graham header but the keeper somehow throw up a hand to push the ball over the crossbar.

Ronny Deila' men were hanging on at the end, having dominated for long spells and getting off to a perfect start.

Just as they did at Partick Thistle on Wednesday, Celtic opened the scoring inside the first minute.

Nir Bitton clipped a straight ball through the middle from inside his own half and three defenders in blue were left stranded as Griffths ran in to stroke a first-time finish past advancing goalkeeper Alan Mannus.

Griffiths, who missed the midweek win at Firhill with an ankle injury, was a lively presence as the home side found themselves pinned back.

A Virgil van Dijk header from corner landed at the striker's feet but he could only touch it into the arms of Mannus.

The hosts' best chance of the first half came from a great O'Halloran cross which was headed narrowly wide by Chris Kane, on as an early replacement for the inured Murray Davidson.

Mannus used an outstretched foot to thwart Griffiths, who raced onto a smart pass from Johansen, and the Northern Irish keeper pushed away a fierce rising shot from the same player soon after.

He then produced an excellent flying save to keep out a powerful 25-yard strike from Gary Mackay-Steven that looked destined for the top corner.

Saints worked hard to deny Celtic space after an early battering but their graft could only stem the flow until seven minutes into the second half when Johansen finished off a neat move in style.

Griffiths headed a lofted pass from Stuart Armstrong into the Norwegian's path and the midfielder controlled with his chest before keeping the ball up with his left foot and smashing in a right-foot finish from close range.

St Johnstone have now gone five games without a victory

Celtic withdrew Griffiths and Armstrong, perhaps with an eye on Thursday's Europa League meeting with Inter Milan.

And St Johnstone took advantage of a drop in intensity from the visitors to reduce the deficit on 72 minutes.

Tam Scobbie's low cross from the left was stabbed towards goal by a lunging Kane at the near post and Gordon could not gather, with O'Halloran slamming the rebound off the keeper's knee high into the net.

Liam Henderson went close with a shot on the turn from the edge of the penalty box and the Celtic substitute was denied a tap-in by a Brian Easton block.

Gordon should have done better at the St Johnstone goal but atoned with his double save on 88 minutes - stopping Graham's close-range header before making a fabulous reflex save from Mackay's powerful follow-up.

There was still time for a James McFadden free-kick to get round Celtic's defensive wall but Gordon was right behind it to secure victory for his side.